JP2013160290A - Assembling method and tool of final reduction gear - Google Patents

Abstract

A method of assembling a final reduction gear and a jig used therefor that can be reliably and easily performed.
A differential case (30), a tapered roller bearing (80), a housing (50), and a shim (90) are provided, and an outer fitting part (51) includes a first outer fitting part (61) of a first housing (60) and a second outer part of a second housing (70). A method of assembling the final reduction gear device 1 that is configured by combining the fitting portion 71, and the jig 200 is attached to the boss portion 32 by screwing the protrusion 230 into the oil guide groove 35. The jig fitting step for pressing the shim 90 against the tapered roller bearing 80 and the first outer fitting portion 61 and the second outer fitting portion 71 are combined to constitute the outer fitting portion 51, and the outer fitting portion 51 is formed into the tapered roller bearing. The housing is assembled with the outer fitting portion 51 and the tapered roller bearing 80 and the jig is removed from the boss portion 32. And, including the.
[Selection] Figure 6

Description

  The present invention relates to a method of assembling a final reduction gear and a jig.

  In a rear-wheel drive or four-wheel drive four-wheeled vehicle, the power from the transmission is transmitted to the center of the left and right rear wheels via a propeller shaft that extends in the front-rear direction at the center in the vehicle width direction. It is transmitted to the reduction gear. The final reduction gear is integrated with the companion flange to which the power of the propulsion shaft is input, the drive pinion shaft splined to the companion flange, the ring gear that meshes with the drive pinion gear of the drive pinion shaft and deflects the power by 90 °, and the ring gear A rotating differential case, a differential gear (pinion gear, side gear) provided in the differential case, and a housing (carrier housing) for accommodating the differential case and the like are configured.

  Specifically, for example, the differential case is rotatably supported by the housing via a tapered roller bearing (bearing). The tapered roller bearing includes an inner ring that fits outside a cylindrical boss formed at both ends of the differential case, an outer ring that fits inside the housing, and a plurality of rollers that roll between the inner ring and the outer ring. The outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring are frustoconical tapered surfaces. In such a tapered roller bearing, if there is a gap between the outer peripheral surface of the inner ring and the outer peripheral surface of the roller, and a gap between the inner peripheral surface of the outer ring and the outer peripheral surface of the roller, the gear meshing reaction force causes the gear. As a result, the entire gear moves. As a result, the meshing between the gears becomes abnormal, and there is a risk that abnormal noise may occur or durability may be lowered.

  More specifically, the inner side surface in the axial direction of the inner ring is in contact with the outer side surface in the axial direction of the differential case. On the other hand, the outer side surface in the axial direction of the outer ring is configured to abut on the inner wall surface of the housing (the outer fitting portion that is fitted on the outer ring) via a thin ring-shaped shim (preloading member) (see Patent Document 1). ). That is, the taper roller bearing is configured to be sandwiched between the differential case and the housing in the axial direction. The axial direction is the rotational axis direction of the differential case, and is the left-right direction (vehicle width direction) of the vehicle.

  That is, in the axial direction, the shim is sandwiched between the outer ring of the tapered roller bearing and the housing. Then, by adjusting the thickness of the shim, the gap between the outer peripheral surface of the inner ring and the outer peripheral surface of the roller and the gap between the inner peripheral surface of the outer ring and the outer peripheral surface of the roller are adjusted. Yes.

  By the way, the housing is constituted by a cast product, for example, and is generally divided into two parts in consideration of workability at the time of casting and assembly workability at the time of accommodating a differential case, and the division position is It is determined in consideration of machining of the housing, reduction in size and weight, strength, and the like. For example, the division position is set on the rotation axis of the differential case, that is, the virtual division plane is set so as to pass through the rotation axis.

However, when the division position is set on the rotation shaft of the differential case, there is a possibility that inconvenience occurs in the assembling work of the tapered roller bearing and the like.
That is, when the division position is set on the rotation shaft of the differential case, the housing is divided into a semicircular first housing and a semicircular second housing in the axial view, and is fitted on the tapered roller bearing. The outer fitting portion of the housing is divided into a semicircular arc first outer fitting portion of the first housing and a semicircular arc second outer fitting portion of the second housing.

  In the case of such a configuration, for example, a taper roller bearing externally fitted to the boss portion of the differential case is overlaid with a shim on the first housing, and then the second housing is assembled. That is, after the taper roller bearing and the shim half are fitted by the first outer fitting portion of the first housing, the taper roller bearing and the other half of the shim are fitted by the second outer fitting portion of the second housing. become.

  However, after the taper roller bearing and the shim half are fitted by the first outer fitting portion, before the other half of the taper roller bearing and the shim is fitted by the second outer fitting portion, the taper roller bearing and the shim half are fitted by the first outer fitting portion. 1 Since the outer fitting part is fitted outside, the remaining half of the tapered roller bearing etc. falls axially outward (opens outward in the axial direction), and the remaining half of the shim is less than the virtual regular mounting surface. May also come off axially outward.

  When the second housing is assembled with the tapered roller bearing and the remaining half of the shim tilted outward in the axial direction, the first housing and / or the second housing may be deformed, And / or the inner surface of the second housing may be damaged.

  Therefore, in Patent Document 1, a female screw part is formed on the axially outer side portion of the inner peripheral surface of the boss part, and a jig is screwed into the female screw part and a shim is pressed with the jig. The first housing and the second housing are combined.

JP 2010-43672 A

  However, in Patent Document 1, since the internal thread portion is processed and formed only for screwing the jig, the processing cost increases. Further, since the female screw is formed, the boss portion (difference case) becomes longer in the axial direction, which hinders the reduction in size and weight of the differential case (final reduction gear).

  Accordingly, the present invention provides an assembly method of a final reduction gear and a jig used therefor that can reliably and easily assemble a small and lightweight final reduction gear without causing an increase in processing cost. Is an issue.

  As a means for solving the above-mentioned problems, the present invention has a cylindrical boss part formed with a spiral oil guide groove for guiding oil on the inner peripheral surface at both ends, and is centered on a predetermined rotation axis. A differential case that rotates as a bearing, a bearing that is externally fitted to the boss portion, a housing that is externally fitted to the bearing and extends in the circumferential direction, and that rotatably accommodates the differential case; An annular shim sandwiched between outer fitting portions, wherein the housing is configured by combining a first housing and a second housing, and the outer fitting portion includes the first outer fitting portion of the first housing and the first housing. 2 is a method of assembling the final reduction gear, which is configured in combination with the second outer fitting portion of the housing, and uses a jig in which a protrusion that engages with the spiral oil guide groove is formed on the outer peripheral surface. The oil plan A jig is attached to the boss by screwing into the groove, and a jig attaching step of pressing the radial inner edge of the shim against the bearing with the jig, and the first housing and the second housing. By combining, the first outer fitting portion and the second outer fitting portion are combined to form the outer fitting portion, the outer fitting portion is externally fitted to the bearing, and the outer fitting portion and the bearing Assembly of the final reduction gear, comprising: a housing combination step of sandwiching the shim in a step; and a jig removing step of removing the jig from the boss portion by removing the protrusion from the oil guide groove. Is the method.

  According to such a configuration, in the jig attaching step, the protrusion is screwed into the oil guide groove to attach the jig to the boss portion, and the radial inner edge of the shim is pressed against the bearing with this jig.

Next, in the housing combining step, by combining the first housing and the second housing, the first outer fitting portion and the second outer fitting portion are combined to form an outer fitting portion, and this outer fitting portion is attached to the bearing. The shim is sandwiched between the outer fitting portion and the bearing.
In this case, the jig presses the radially inner edge of the shim against the bearing, and the shim does not fall (open) axially outward, so that the first housing and the second housing are not deformed. Then, the outer fitting portion is configured by combining the first outer fitting portion and the second outer fitting portion reliably and easily without damaging the inner surfaces of the first outer fitting portion and the second outer fitting portion. The outer fitting portion can be fitted onto the bearing, and the shim can be sandwiched between the outer fitting portion and the bearing.

  Next, in the jig removing step, when the protrusion is removed from the oil guide groove and the jig is removed from the boss portion, the final reduction gear is obtained.

  Thus, without forming a screw part dedicated to mounting the jig, the jig is fixed to the boss part by utilizing the spiral oil guide groove that guides the oil formed on the inner peripheral surface of the boss part. Therefore, the processing cost of the boss portion does not increase. Further, since the boss portion is not elongated in the axial direction due to the formation of the screw portion dedicated to mounting the jig, a small and lightweight final reduction device is obtained.

  Further, as means for solving the above-mentioned problem, the present invention provides a jig used in the method of assembling the final reduction gear, wherein the insertion portion is inserted into the hollow portion of the boss portion, and the outer periphery of the insertion portion. A jig comprising: a protrusion formed on a surface and screwed into the oil guide groove; and a shim pressing portion that is integral with the insertion portion and presses the shim.

According to such a structure, a jig | tool can be attached to a boss | hub part by screwing the protrusion formed in the outer peripheral surface of an insertion part to the oil guide groove of a boss | hub part.
Then, in a state where the jig is attached to the boss portion, the shim can be pressed against the bearing by the shim pressing portion that is integral with the insertion portion.

  In the jig, the shim pressing portion is preferably cylindrical.

  According to such a configuration, the shim can be stably pressed against the bearing by the cylindrical shim pressing portion.

  In the jig, the protrusion is preferably a spiral protrusion.

  According to such a configuration, since the protrusion is a spiral protrusion, the attachment state of the jig to the boss portion is stabilized.

  ADVANTAGE OF THE INVENTION According to this invention, the assembly method of the final reduction gear apparatus which can perform the assembly of a small and lightweight final reduction gear apparatus reliably and simply, without causing the increase in processing cost, and the jig | tool used for this can be provided.

It is a plane sectional view of the final reduction gear device concerning this embodiment. It is a plane sectional view of the important section of the final reduction gear device concerning this embodiment. It is a figure of the jig | tool which concerns on this embodiment, Comprising: (a), (b) is a perspective view, (c) is a top view (side view). It is a plane sectional view explaining the assembly method of the final reduction gear device concerning this embodiment. It is a plane sectional view explaining the assembly method of the final reduction gear device concerning this embodiment. It is a plane sectional view explaining the assembly method of the final reduction gear device concerning this embodiment. It is a plane sectional view explaining the assembly method of the final reduction gear device concerning this embodiment. It is a plane sectional view explaining the assembly method of the final reduction gear device concerning this embodiment. It is a plane sectional view explaining the assembly method of the final reduction gear device concerning this embodiment. It is a plane sectional view explaining the assembly method of the final reduction gear device concerning this embodiment.

  An embodiment of the present invention will be described with reference to FIGS.

  A final reduction gear 1 according to the present embodiment will be described with reference to FIGS. Here, the power of an internal combustion engine (not shown) arranged on the front side of the four-wheeled vehicle is transmitted through a transmission (not shown), a propulsion shaft (not shown), and a viscous joint 100 to drive the pinion of the final reduction gear 1. A configuration in which the power is input to the shaft 10 and the final reduction gear 1 deflects this power by 90 ° and is transmitted to the left and right rear wheels is illustrated. That is, the viscous joint 100 and the final reduction gear 1 are mounted on a four-wheeled vehicle, and the propulsion shaft, the viscous coupling 100, and the drive pinion shaft 10 extend in the front-rear direction at the center in the vehicle width direction. The rotation axis O of the differential case 30 that constitutes is extended in the left-right direction (vehicle width direction).

  However, the power source may be an electric motor in addition to an internal combustion engine (such as a reciprocating engine). Further, the viscous joint 100 may be provided in the middle of the propulsion shaft (not shown), and the rear end of the propulsion shaft may be connected to the drive pinion shaft 10.

≪Configuration of viscous joint≫
Viscous joint 100 has a silicone oil sealed therein when there is a difference between the rotational speed of outer plate 130 that rotates in conjunction with the front wheel and the rotational speed of inner plate 140 that rotates in conjunction with the rear wheel. The power is transmitted between the outer plate 130 (propulsion shaft) and the inner plate 140 (drive pinion shaft 10) using the shearing force.

  The viscous joint 100 includes a bottomed cylindrical outer housing 110 having a bottom wall portion 111 on the front side, a cylindrical inner hub 121 disposed on the central axis of the outer housing 110 and extending in the front-rear direction, the outer housing 110, and A plurality of outer plates 130 and inner plates 140 accommodated in a ring-shaped space formed between the inner hubs 121 and a ring-shaped cover 151 are provided.

  The front end of the outer housing 110 is connected to the rear end of a propulsion shaft (not shown). Thereby, the outer housing 110 rotates integrally with the propulsion shaft.

  The inner hub 121 is externally fitted (spline coupled) to a substantially front half of the drive pinion shaft 10. Thereby, the inner hub 121 rotates together with the drive pinion shaft 10.

  The front end 11 (tip) of the drive pinion shaft 10 projects forward from the inner hub 121. The lock nut 122 is screwed into the protruding portion through the washer 123 and the washer 124. Thus, the inner hub 121 and the outer housing 110 are locked by the lock nut 122, that is, the inner hub 121 and the outer housing 110 are prevented from being detached from the drive pinion shaft 10.

  A ball bearing 125 (bearing) is provided between the inner hub 121 and the bottom wall portion 111 of the outer housing 110. Thereby, the inner hub 121 and the outer housing 110 are relatively rotatable.

  A seal ring 136 is provided between the inner hub 121 and the bottom wall portion 111 of the outer housing 110. The seal ring 136 seals silicon oil in the outer housing 110.

  The rear end of the inner hub 121 protrudes rearward from the outer housing 110, and an oil seal 127 is provided between the protruding portion and a first housing 60 described later. As a result, water, dust, and the like are blocked by the oil seal 127 and do not enter the tapered roller bearing 13 described later.

The outer plate 130 and the inner plate 140 are ring-shaped thin plates, and are accommodated in a ring-shaped space between the outer housing 110 and the inner hub 121 in a state where they are alternately stacked in the front-rear direction.
The splines formed on the outer peripheral surface of the outer plate 130 are fitted with the splines formed on the inner peripheral surface of the outer housing 110. As a result, the outer plate 130 rotates integrally with the outer housing 110.
The splines formed on the inner peripheral surface of the inner plate 140 are fitted with the splines formed on the outer peripheral surface of the inner hub 121. Thereby, the inner plate 140 rotates integrally with the inner hub 121.

  In addition, silicone oil is sealed in the outer housing 110, and this silicone oil is interposed between the outer plate 130 and the inner plate 140. When a difference in rotational speed between the outer plate 130 and the inner plate 140 occurs, a shearing force is generated by the silicone oil therebetween, and power is transmitted between the outer plate 130 and the inner plate 140.

  The cover 151 is attached to the outer housing 110 by a circlip 152 behind the laminated body of the outer plate 130 and the inner plate 140. Thereby, the cover 151 is prevented from coming out of the outer housing 110. A bearing 153 (bearing) is provided between the cover 151 and the inner hub 121. Thereby, the cover 151 and the inner hub 121 are relatively rotatable.

  An O-ring 154 is provided between the cover 151 and the outer housing 110, and a seal ring 155 is provided between the cover 151 and the inner hub 121. The O-ring 154 and the seal ring 155 seal the silicon oil in the outer housing 110.

  The cover 151 is screwed with a bolt 156 that is removed when silicon oil is injected. In addition, the cover 151 is formed with an air vent hole 157 that serves as a passage for air to the outside when silicon oil is injected. FIG. 1 shows a state in which a ball is press-fitted into the air vent hole 157 and the air vent hole 157 is closed.

≪Configuration of final reduction gear≫
The configuration of the final reduction gear 1 will be described.
The final reduction gear 1 includes a drive pinion shaft 10, a ring gear 20, a differential case 30, two pinion gears 41 and two side gears 42, a housing 50 that rotatably accommodates the differential case 30, and a differential case 30 with respect to the housing 50. Are provided with two tapered roller bearings 80 and two shims 90. As will be described later, the housing 50 is configured by combining a first housing 60 and a second housing 70.
Since the final reduction gear 1 is substantially bilaterally symmetrical, the left side will be mainly described.

<Drive pinion shaft>
The drive pinion shaft 10 includes a frustoconical drive pinion gear 12 at the rear end thereof. The drive pinion gear 12 meshes with the ring gear 20 so that the power of the drive pinion shaft 10 is deflected by 90 °.

  The drive pinion shaft 10 is rotatably supported by the first housing 60 via a tapered roller bearing 13 and a tapered roller bearing 14.

  A collapsible spacer 15 (collapsible spacer) is interposed between the taper roller bearing 13 and the taper roller bearing 14. The collapsible spacer 15 has a cylindrical shape, is a component that can be elastically deformed in the axial direction (front-rear direction), and applies axial preload to the tapered roller bearing 13 and the tapered roller bearing 14.

  A shim 16 is interposed between the taper roller bearing 14 and the drive pinion gear 12. The shim 16 has a ring shape and is adjusted in position so that the engagement between the drive pinion gear 12 and the ring gear 20 is optimal. The thickness of the shim 16 is determined based on the processing accuracy of the first housing 60 that supports the tapered roller bearing 14 in the axial direction.

<Ring gear, differential case, pinion gear, side gear>
The differential case 30 rotates about a rotation axis O extending in the left-right direction, and includes a spherical shell-shaped differential case body 31, cylindrical boss portions 32, 32 formed at both ends of the differential case body 31, and a ring, respectively. Shaped flange portion 33.

  The ring gear 20 is fastened to the flange portion 33 by bolts 34. Thereby, the ring gear 20 and the flange part 33 (difference case 30) rotate integrally. However, the ring gear 20 and the differential case 30 may be configured as an integrally cast product.

The differential case body 31 has a gear housing chamber for housing the pinion gear 41 and the side gear 42 therein.
Specifically, a pinion shaft 43 is fixed to the differential case body 31, and the pinion shaft 43 extends in a radial direction (front-rear direction in FIG. 1) of the differential case body 31. Each pinion gear 41 is rotatably attached to the pinion shaft 43 with the pinion shaft 43 as a center of rotation.

  Each side gear 42 is rotatably arranged around the rotation axis O on each of the left and right sides of the pinion shaft 43 and meshes with the two pinion gears 41 and 41. A thrust washer 44 is interposed between the rear surface (axial outer surface) of each side gear 42 and the differential case body 31.

  A drive shaft (not shown) that rotates in conjunction with the left or right rear wheel is inserted into the back surface of each side gear 42, and the side gear 42 and the drive shaft are splined. As a result, the side gear 42 and the drive shaft rotate together.

  A left or right drive shaft (not shown) is inserted through the hollow portion of each boss portion 32. A spiral oil guide groove 35 is formed on the inner peripheral surface of each boss portion 32. The oil guide groove 35 is a groove that guides oil present outside the tapered roller bearing 80 to the center (center in the vehicle width direction) of the differential case 30. The direction of the spiral of the oil guide groove 35 is opposite to the left and right because the oil is guided to the center when the drive shaft rotates in the forward direction corresponding to the forward direction of the vehicle.

  In addition, the oil is the bottom of the housing 50 and the oil in the oil pool formed below the differential case 30 is scraped up by the rotating ring gear 20 and the flange portion 33 and the oil attached to the inner surface of the housing 50 is removed. The oil is dropped and guided to the boss portion 32 of the differential case 30 by a groove (not shown) for guiding oil to the outside of the tapered roller bearing 80 and guided to the spiral groove 35 through a notch formed at the tip of the boss portion 32.

<Housing, taper roller bearing, shim>
The housing 50 accommodates the differential case 30 rotatably via taper roller bearings 80 and 80.

Hereinafter, with reference to FIG. 2 as appropriate, the left side of the final reduction gear 1 will be described more specifically.
The tapered roller bearing 80 includes an inner ring 81 fitted on the boss portion 32, an outer ring 82 fitted on the housing 50, and a plurality of cylindrical rollers 83 that roll between the inner ring 81 and the outer ring 82. It is equipped with. The outer peripheral surface of the inner ring 81 and the inner peripheral surface of the outer ring 82 are truncated conical tapered surfaces. Further, the inner peripheral surface of the inner ring 81 is in contact with and in contact with the outer peripheral surface of the boss portion 32, and the inner end surface of the inner ring 81 is in contact with the differential case body 31. The inner side means the center side in the vehicle width direction.

  On the other hand, the housing 50 has an outer fitting portion 51 that is fitted on the tapered roller bearing 80 and extends in the circumferential direction. The outer fitting portion 51 has a substantially L shape, and in a cross-sectional view, an axial direction portion 52 that extends in the axial direction (left-right direction), and a radial direction portion that extends radially inward from an outer portion of the axial direction portion 52. 53.

  The axial direction portion 52 is externally fitted to the outer ring 82.

  On the other hand, the radial portion 53 is disposed on the outer side in the axial direction of the outer ring 82, and a shim 90 is interposed between the radial portion 53 and the outer ring 82. In the axial direction, the shim 90 is in the radial direction. It is sandwiched between the portion 53 and the outer ring 82. The thickness of the shim 90 is set based on the processing accuracy of the differential case 30 and the housing 50 and the size of the preload to be applied to the tapered roller bearing 80.

  The width (diameter length) of the shim 90 is set to a length in which the shim 90 protrudes from the radial portion 53 in the radial direction. That is, the radially inner edge 91 of the shim 90 faces the outside in the axial direction (left-right direction).

  Thus, since the radial inner edge 91 of the shim 90 protrudes from the radial part 53 and faces the outside, the jig 200 and the jig 200 are pressed while being pressed by the jig 200 described later. The first housing 60 and the second housing 70 can be combined without interfering with the radial portion 53, and at the same time the first housing 60 and the second housing 70 are combined, the radial portion 53 is an outer ring. The shim 90 is sandwiched between 82 and 82.

  The housing 50 is divided by a dividing surface which is a vertical surface passing through the rotation axis O, and is configured by combining a first housing 60 on the front side and a second housing 70 on the rear side. The combined state is maintained by bolts (not shown) that fasten the first housing 60 and the second housing 70 to each other.

  When the housing 50 is divided into the first housing 60 and the second housing 70, the outer fitting portion 51 is a part of the first housing 60 and has a semicircular arc-shaped first outer fitting portion 61 and the second housing. 70 is divided into a semicircular arc-shaped second outer fitting portion 71. That is, the circular outer fitting portion 51 is configured by combining a semicircular arc-shaped first outer fitting portion 61 and a semicircular arc-shaped second outer fitting portion 71.

≪Jig≫
Next, the jig 200 used when assembling the final reduction gear 1 will be described with reference to FIG. Here, the jig 200 that is screwed into the left boss portion 32 will be described.

  The jig 200 protrudes on the center axis line from the columnar-shaped operation part 210 and one end surface (upper surface in FIG. 3) of the operation part 210, and is inserted into the hollow part of the boss part 32 (see FIG. 1). Insertion portion 220, a spiral protrusion 230 (protrusion) formed on the outer peripheral surface of the insertion portion 220, and a cylindrical shim press protruding from the outer edge portion of one end surface (upper surface in FIG. 3) of the operation portion 210 Part 240. The jig 200 is an integrally molded product, and the operation unit 210, the insertion unit 220, the protrusion 230, and the shim holding unit 240 are integrated.

  A hexagonal hole 211 into which a tool (hexagonal wrench) for rotating the jig 200 is inserted is formed on the other end surface (lower surface in FIG. 3) of the operation unit 210.

The protrusion 230 is a portion that is screwed into the oil guide groove 35 formed on the inner peripheral surface of the left boss portion 32 in FIG. 1. That is, the number (number of stripes), pitch, and winding direction of the protrusions 230 correspond to the number (number of stripes), pitch, and winding direction of the oil guide grooves 35.
Since the winding directions of the left and right oil guide grooves 35 are opposite to each other, the winding direction of the ridges in the jig screwed into the right boss portion 32 is opposite to that shown in FIG.

  When the jig 200 is attached to the boss portion 32 (see FIG. 7), the shim pressing portion 240 is a portion that presses the radially inner edge 91 of the shim 90 toward the outer ring 82 on the inner side in the axial direction. The outer diameter of the shim pressing portion 240 is set to be equal to or smaller than the inner diameter of the radial portion 53 of the outer fitting portion 51 (see FIG. 10). As a result, the first housing 60 and the second housing 70 can be combined while the shim 90 is pressed by the shim holding portion 240.

  A boundary portion between the inner peripheral surface of the shim pressing portion 240 and one end surface (upper surface in FIG. 3) of the operation portion 210 has an R shape, and the shim pressing portion 240 becomes thicker as the operation portion 210 is approached. Thereby, it is easy to mold the jig 200 using a mold or the like, and the strength of the shim pressing portion 240 is increased, and the shim pressing portion 240 is hardly deformed.

≪Method of assembling the final reduction gear≫
Next, a method for assembling the final reduction gear 1 will be described with reference to FIGS.
The method of assembling the final reduction gear 1 includes a viscous joint attachment process (see FIG. 4), a jig attachment process (see FIGS. 5 to 7), a housing combination process (see FIGS. 8 to 10), and a jig removal. And a process.

<Viscosity joint installation process>
As shown in FIG. 4, the viscous joint attaching step is a step of attaching the viscous joint 100 to the first housing 60.
After the drive pinion shaft 10 is inserted into the shim 16 and the tapered roller bearing 14, the drive pinion shaft 10 is inserted from the inside of the first housing 60 to the outside. Next, the collapsible spacer 15 and the tapered roller bearing 13 are attached to the drive pinion shaft 10 protruding from the first housing 60 in this order. Next, the drive pinion shaft 10 is inserted into the hollow portion of the inner hub 121, and the drive pinion shaft 10 and the inner hub 121 are spline-connected.

  Next, after attaching a washer 124 and a washer 123 to the front end 11 of the drive pinion shaft 10 protruding forward from the inner hub 121, a lock nut 122 is screwed into the front end 11. When the lock nut 122 is tightened in this way, the collapsible spacer 15 is elastically deformed in the axial direction (front-rear direction), and axial preload is applied to the tapered roller bearing 13 and the tapered roller bearing 14.

<Jig mounting process>
As shown in FIG. 5 to FIG. 7, the jig attaching step is performed by attaching the tapered roller bearing 80 and the shim 90 to the boss portion 32 of the differential device (differential device) separately assembled, and then the left and right boss portions. In this step, the jigs 200 are respectively attached to 32 and the shim 90 is pressed by the jigs 200.
The differential device includes a differential case 30, a pinion gear 41, a side gear 42, and a pinion shaft 43.

  That is, after aligning the protrusion 230 of the jig 200 and the oil guide groove 35 of the boss portion 32, the protrusion 230 is screwed into the oil guide groove 35 when the jig 200 is rotated in a predetermined rotation direction. At the same time, the jig 200 advances toward the inner side in the axial direction (center side in the vehicle width direction) while rotating, and the shim pressing portion 240 abuts against the radially inner edge 91 of the shim 90. Then, the shim pressing portion 240 is in a state (pressed state) in which the radial inner edge 91 of the shim 90 is pressed against the outer ring 82 of the tapered roller bearing 80 (see FIGS. 6 and 7).

  In this case, for example, the tapered roller bearing 80 and the shim 90 are arranged so that the shim 90 is in a predetermined position with respect to the tapered roller bearing 80, that is, the shim 90 is not displaced in the radial direction (front and rear, up and down, etc.). A jig 200 is attached to the boss portion 32 and pressed against the shim 90 in a state where a cylindrical alignment adapter (not shown) having an inner diameter corresponding to the outer diameter is fitted onto the tapered roller bearing 80 and the shim 90. Thereafter, the alignment adapter may be removed.

<Housing combination process>
As shown in FIGS. 8 to 10, the housing combination process is a process in which the first housing 60 and the second housing 70 are combined to form the housing 50 and the housing 50 accommodates the differential case 30 and the like.
Here, a configuration in which the differential case 30 and the like are attached to the first housing 60 first is illustrated, but a configuration in which the differential case 30 and the like are attached to the second housing 70 first is also possible.

As shown in FIG. 8, the front half of the shim 90 pressed by the jig 200 is attached to the first housing 60. In other words, the tapered roller bearing 80 and the front half of the shim 90 are fitted into the semicircular arc-shaped first outer fitting portion 61 of the first housing 60.
In this case, since the shim 90 is pressed by the jig 200, the rear half of the shim 90 does not fall outward in the axial direction (left-right direction) after being fitted into the first outer fitting portion 61.

Next, as shown in FIG. 9, the rear half of the shim 90 pressed by the jig 200 is attached to the second housing 70. That is, the taper roller bearing 80 and the rear half of the shim 90 are fitted into the semicircular arc second outer fitting portion 71 of the second housing 70.
In this case, the shim 90 is pressed down, and the rear half of the shim 90 is not tilted outward in the axial direction (left-right direction), so that it can be easily fitted into the second outer fitting portion 71 (see FIG. 10). .
Then, the 1st housing 60 and the 2nd housing 70 are fastened with a volt | bolt (not shown), and a combined state is maintained.

<Jig removal process>
The jig removing step is a step of removing the jig from the boss portion by rotating the jig 200 in a predetermined direction and removing the protrusion 230 from the oil guide groove 35. When the jig 200 is removed in this manner, the final reduction gear 1 is obtained.

≪Effect of assembly method of final reduction gear≫
According to such a method of assembling the final reduction gear 1, the following effects are obtained.
Since the jig 200 is attached / detached to / from the boss portion 32 using the spiral oil guide groove 35 formed on the inner peripheral surface of the boss portion 32, a groove dedicated to the attachment of the jig 200 is provided in the boss portion 32. The boss portion 32 is not elongated in the axial direction, and the processing cost of the differential case 30 does not increase. The differential case 30 is not hindered from being reduced in size and weight.

≪Modification≫
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, For example, you may change as follows.

  In the above-described embodiment, the configuration in which the protrusion of the jig 200 that is screwed into the oil guide groove 35 is the spiral continuous protrusion 230 is exemplified, but, for example, along the spiral oil guide groove 35. A plurality of protrusions arranged and discontinuous may be used.

  In the above-described embodiment, the shim pressing portion 240 is illustrated as a cylindrical shape that is continuous in the circumferential direction, but other shapes may be used. For example, the shim pressing portion is an elongated cylindrical shape that extends upward from the outer edge portion of the upper surface of the columnar operation unit 210, and the elongated cylindrical shim pressing portions are equally spaced in the circumferential direction (for example, 90 ° intervals). It is good also as a structure provided in.

  In the above-described embodiment, the housing 50 is exemplified by a configuration in which the first housing 60 and the second housing 70 are combined. However, for example, in addition to this, a configuration in which a third housing is combined may be used. That is, the housing 50 is not limited to the two-piece configuration, and may be a three-piece or more configuration.

  In the above-described embodiment, the dividing surface of the housing 50, that is, the mating surface of the first housing 60 and the second housing 70 is illustrated as being in the vertical direction. .

  In the above-described embodiment, the configuration in which the operation unit 210 and the insertion unit 220 of the jig 200 are solid is exemplified. However, for example, the operation unit 210 and / or the insertion unit 220 may be hollow.

  In the above-described embodiment, the configuration in which the bearing that fits outside the boss portion 32 and fits inside the housing 50 is the tapered roller bearing 80. However, other types of bearings, for example, a ball bearing may be used. .

  In the above-described embodiment, the configuration in which the hexagonal hole 211 into which the tool (hexagonal wrench) for rotating the jig 200 is inserted is illustrated in the operation unit 210 (see FIG. 3B). For example, the shape of the hole may be changed to a square hole into which a box wrench is inserted, or a hexagonal columnar protrusion for inserting a socket wrench may be formed instead of the hexagonal hole 211.

DESCRIPTION OF SYMBOLS 1 Final reduction device 30 Differential case 32 Boss part 35 Oil guide groove 50 Housing 51 Outer fitting part 60 First housing 61 First outer fitting part 70 Second housing 71 Second outer fitting part 80 Tapered roller bearing (bearing)
90 Shim 91 Radial inner edge 200 Jig 220 Insertion part 230 Projection (protrusion)
240 Shim holder O Rotating shaft

Claims (4)

A differential case that has a cylindrical boss portion formed with a spiral oil guide groove that guides oil on the inner peripheral surface at both ends and rotates around a predetermined rotation axis, and a bearing that fits around the boss portion A housing having an outer fitting portion that is fitted on the bearing and extending in the circumferential direction, and that rotatably accommodates the differential case, and an annular shim sandwiched between the bearing and the outer fitting portion in the axial direction. The housing is configured by combining a first housing and a second housing, and the outer fitting portion is configured by combining a first outer fitting portion of the first housing and a second outer fitting portion of the second housing. A method of assembling the final reduction gear,
Using a jig with a protrusion formed on the outer peripheral surface to be screwed into the spiral oil guide groove, the jig is attached to the boss portion by screwing the protrusion into the oil guide groove. A jig mounting step of pressing the shim radial inner edge against the bearing;
By combining the first housing and the second housing, the first outer fitting portion and the second outer fitting portion are combined to form the outer fitting portion, and the outer fitting portion is fitted to the bearing. And a housing combination step of sandwiching the shim between the outer fitting portion and the bearing,
By removing the protrusion from the oil guide groove, a jig removing step for removing the jig from the boss part,
A method of assembling the final reduction gear. A jig used in the method of assembling the final reduction gear according to claim 1,
An insertion part inserted through the hollow part of the boss part;
A protrusion formed on the outer peripheral surface of the insertion portion and screwed into the oil guide groove;
A shim holding portion that is integral with the insertion portion and holds the shim;
A jig characterized by comprising: The jig according to claim 2, wherein the shim pressing portion is cylindrical. The jig according to claim 2 or 3, wherein the protrusion is a spiral protrusion.

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